# SLR: Amalgamation (summed) logratio In easyCODA: Compositional Data Analysis in Practice

## Description

Computation of a single amalgamation (summed) logratio

## Usage

 `1` ```SLR(data, numer=NA, denom=NA, weight=TRUE) ```

## Arguments

 `data` A compositional data frame or matrix `numer` Vector of parts in the numerator `denom` Vector of parts in the denominator `weight` Logical indicating if a varying weight is returned (default:`TRUE`). If `FALSE`, a weight based on equally-weighted parts is returned. Alternatively a positive weight can be specified.

## Details

The function `SLR` computes a single amalgamation logratio based on the specified numerator and denominator parts that define the two summations in the ratio.

## Value

 `LR` The amalgamation (summed)) logratio (SLR) `LR.wt` The weight assigned to the SLR

## Author(s)

Michael Greenacre

## References

Aitchison, J. (1986), The Statistical Analysis of Compositional Data, Chapman & Hall.
Greenacre, M. (2018), Compositional Data Analysis in Practice, Chapman & Hall / CRC Press.

`ILR`, `ALR`, `CLR`, `PLR`, `LR`

## Examples

 ```1 2``` ```data(veg) SLR(veg, numer=1, denom=2:3) ```

### Example output

```Loading required package: ca
This is vegan 2.5-7

Attaching package: ‘ellipse’

The following object is masked from ‘package:graphics’:

pairs

\$LR
Asparagus      Beans(soya)         Broccoli          Carrots
-0.59015191      -0.32072118      -0.05241199      -2.35713896
Corn        Mushrooms           Onions             Peas
-2.05846331      -1.60130000      -2.14926421      -1.00785419
Potatoes(boiled)          Spinach
-2.46428736      -0.34045070

\$LR.wt
[1] 0.1873699
```

easyCODA documentation built on Sept. 20, 2020, 1:07 a.m.